Synthesis of Chiral Vinylglycines

Article abstract of DOI:10.1021/jo00013a023

(R)- or (S)-benzyl 4-formyl-2,2-dimethyl-3-oxazolidinecarboxylate (7a) and (R)- or (S)-1,1-dimethylethyl 4-formyl-2,2-dimethyl-3-oxazolidinecarboxylate (7b), readily available from serine, react with Wittig reagents to give alkenes 8.Selective deprotection followed by oxidation of the resulting unsaturated amino alcohols 9 provides vinylglycines 5 of defined configuration (>95percent ee) and double-bond geometry.D-Vinylglycines are obtained from L-serine, and conversely, D-serine gives β,γ-unsaturated amino acids with the L configuration.The double-bond geometry is controlled by the nature of the phosphorous ylide employed.The scope and limitations of this new methodology for the preparation of chiral vinylglycines is examined.